I have been regularly encountering an issue with a USB keyboard and mouse, where the mouse pointer would freeze for several seconds, and the keyboard would experience missed or delayed keystrokes. After a little while, it would release again, but the problem would reoccur again almost immediately.
Having now found a solution, I thought I would share it in case anyone else is experiencing the same issue.
The issue seems to occur only with a USB keyboard and mouse – it did not occur when a PS/2 keyboard and mouse were used, but this was not a solution for me as the PS/2 ports are not compatible with my main keyboard and mouse, not even with USB-to-PS/2 adaptors, and the PS/2 keyboard & trackpad combo I used for testing is not really suitable for everyday use.
The issue was encountered on a SuperMicro X8DTL-3F motherboard with twin Xeon X5680 CPUs, which was being used as a developer Workstation.
The motherboard has BIOS version 2.1b (16-Nov-2012), which I believe is the latest.
This issue affected Ubuntu 14.04 LTS, Ubuntu 18.04 LTS, and Windows 7 Professional. This suggests it is a hardware issue rather than the operating system.
I tried both the on-board USB2 ports, and also an aftermarket USB3 card, but the problem persisted.
I had Legacy USB Support turned off in BIOS as otherwise the USB3 card is not detected under Ubuntu. But even with Legacy USB Support enabled, the problem still persisted.
I initially tried disabling the COM ports in BIOS. My rationale for this was that maybe it was an IRQ issue, or a polling / timeout issue. This change appeared to mitigate the issue somewhat, but didn’t cure it.
I then contacted SuperMicro tech support, and got a reply within 15 mins (outstanding!).
They suggested disabling IPMI by moving the JPB jumper (located between PCIe slot 3 and 4) from the 1-2 position to the 2-3 position, since IPMI is internally connected to USB on this motherboard and could potentially cause issues on the USB bus.
Having done this as well, I have not yet seen the issue re-occur.
NOTE: Simply disabling IPMI in BIOS is not sufficient, as I already had that disabled whilst experiencing the issue.
I have not as yet re-enabled the COM ports, since I do not need them enabled, so I cannot say whether it is solely the IMPI disable that fixes the issue, or whether you need to disable the COM port as well.